Generally, tinting cosmetic materials include volatile solvents therein, so, if a container that contains such a tinting cosmetic material therein fails to maintain a desired airtight sealing function while being kept, the cosmetic material may easily change in quality.
For example, when a cosmetic container that contains foundation used as a base for facial makeup fails to maintain an airtight sealing function, moisture and volatile ingredients of the foundation will vaporize, so the foundation may lose its intrinsic pleasant fragrance and may become hard and easily crack, and the expected life span of the foundation may be shortened.
In an effort to solve the problems, the cosmetic container for containing the tinting cosmetic material is typically configured to prevent the tinting cosmetic material contained therein from changing in quality by providing an airtight structure capable of airtightly closing the inner container when closing the outer lid of the cosmetic container.
In the related art, to provide cosmetic containers having airtight structures, various techniques are proposed. Conventional airtight cosmetic containers are classified into two types: a cosmetic container having a lock type opening/closing structure in which an outer lid hinged to an outer container is opened or closed by operating a lock provided in a part opposed to the outer lid, and a cosmetic container having a threaded type opening/closing structure in which an outer lid hinged to an outer container is opened or closed by rotating internal and external threads in a state in which the outer lid is being closed.
When compared to the latter container that is the container having the threaded type opening/closing structure, the former container that is the container having the lock type opening/closing structure is problematic in that the pressing force of a sealing rib provided in the outer lid is lower than the pressing force of the container having the threaded type opening/closing structure, so the airtight sealing effect formed between the outer lid and the inner container of the cosmetic container having the lock type opening/closing structure gradually becomes reduced. However, the cosmetic container having the lock type opening/closing structure is advantageous in that the outer lid can be easily and simply opened by a one-step process of pressing a button.
Accordingly, the most important technique required by the cosmetic container having the lock type opening/closing structure is a technique that can maximize the airtight sealing effect of the container which can isolate the content contained in the inner container from the environment.
In the conventional airtight cosmetic containers having the lock type opening/closing structures, the methods of realizing the airtight sealing effect of a cosmetic receiving container (inner container) that contains a cosmetic material therein are classified into two types: a first method in which the airtight sealing effect for the container is realized by compressing a hard rib integrated with an outer lid onto a rubber seal (airtight seal member), and a second method in which the airtight sealing effect of the container is realized by airtight contact formed by a combination of airtight contact parts of injection-molded elements.
The first method of realizing the airtight sealing effect using the rubber seal is problematic in that, although the method can provide desired airtight sealing effect within a predetermined initial period of time after a new container is used, the performance of the soft rubber seal may gradually change by the repeated compression of the hard plastic rib onto the rubber seal when repeatedly using the container over a long period of time, so the airtight function of the container will be gradually reduced.
The second method of realizing the airtight sealing effect using injection-molded elements is problematic in that, although the method can provide high work efficiency during a process of assembling the container because the method does not require a separate rubber seal, a seal seat for holding the rubber seal or a process of assembling the rubber seal with the seal seat, the method does necessarily require an airtight structure formed by the airtight contact parts that come into close contact with each other to realize the airtight sealing effect of an inner container (cosmetic receiving container) made of a plastic material (synthetic resin).
The present invention relates to an airtight cosmetic container having the lock type opening/closing structure which can realize a desired airtight sealing effect without using a separate rubber seal.
Examples of such airtight cosmetic containers may be referred to Korean Utility Model Registration No. 20-0200762 (registered on Aug. 11, 2000; patent document 1), and Korean Patent No. 10-1033005 (registered on Apr. 27, 2011; patent document 2).
Patent document 1 discloses a technique in which, when an upper case is closed, the sidewall of an inner cover comes into close and pressure contact with an outward inclined surface provided on an upper part of the outer circumferential surface of an inner container installed in a lower case, thereby realizing an airtight sealing effect for the interior of the inner container.
Patent document 2 discloses a technique in which a close contact rib is provided by extending downward from the lower surface of an inner cover that covers a cosmetic receiving chamber of an inner case, wherein the close contact rib is configured to be elastically bent outward and come into close contact with the inner circumferential surface of the sidewall of the cosmetic receiving chamber, thereby realizing an airtight sealing effect for the cosmetic receiving chamber of the inner case.